NOTES OX COCCID-INFESTING CHALCIDOIDEA — TI. 233 



slips :— («) head and trunk ; (6) legs ; (c) wings ; (d) antennae, and if possible (e) man- 

 dibles and trophi. The proportions of tarsal joints and nervures can be judged with 

 accuracy only when the parts are flatly extended. The method of rapid mounting 

 which has been described gives the best results with material which has merely been 

 dried. It may also be used with spirit material, but alcohol has the defect of rapidly 

 becoming a first-rate macerating solution, unless it is used strong (over 80 per cent.) 

 and the tube is at once carefully sealed. When maceration has set in the wings swell, 

 the upper and lower membranes separating, and very frequently a troublesome 

 muddy deposit clogs the fine discal ciliation ; the muscles toughen and a much 

 longer treatment with potash is required before transference to acetic acid can be 

 made ; the wings also are harder to detach. It cannot indeed be questioned that 

 the best preparations of these organs, giving the crispest images under the microscope, 

 are got from specimens which have never been in any liquid preservative. In 

 detaching the wings, legs or antennae, the dissecting needle should be dipped into oil 

 and passed gently over the surface of the part to be taken off before any pressure is 

 applied at the joint ; when the joint is broken the part adheres to the needle and can 

 be at once put in oil. 



But, while Chalcids of the largest size may be pinned, and medium-sized species 

 packed in tissue paper, it is a distinct advantage to have the smallest forms sent in 

 spirit— not that alcohol is of great value as a preservative, but simply that it prevents 

 shaking of the insects and so protects the chaetotaxy and appendages from those 

 injuries which packing in even the softest tissue paper cannot wholly obviate. Care 

 must be taken to fill the tube completely with spirit and the cork should have a smooth 

 surface and exactly fit the tube. 



It is hardly necessary to add that the foregoing notes apply to material whose 

 external morpholog}^ alone has to be investigated. For histological purposes more 

 elaborate methods of preservation are required. If corrosive sublimate (HgCl), 

 alone or in combination, is used as a fixative, it is perhaps well to remind collectors 

 that washing out with iodine in alcohol must be done immediately after fising. 



In the following pages the use of the word " scrobes " has been abandoned. 

 Properly, the term, denoting the frontal furrow in which the antenna rises, includes 

 (a) the groove behind the scape, (6) the rim (torulus), within which the bulla is 

 accommodated, having at its lower angle the real socket of the antenna (c) and 

 occasionally* extending a little round and below the torulus. Some writers have 

 applied the term (1) to the facial impression ; others (2) to what I call the post 

 scapal hollow ; others again (3) to the torulus proper ; neither (1) nor (2) can be 

 supported, and (3) has propriety only in cases where there is no facial impression and 

 the scapal grooves are obsolete, i.e., when the scrobes are reduced to the toruli alone. 



In describing the abdomen ( $) seven tergites and five sternites may be recognised ; 

 normally the first five tergites are simple and transverse, the sixth bears the spiracles 

 and may be separated into a tergite and two pleural parts — each pleurite with a 

 stigma ; the seventh tergite bears the setigerous processes (2). I can see no 

 objection, for descriptive purposes at least, to numbering the tergites 1-7 and the 

 sternites 1-5 ; to homologise them strictly with the segments to which they belong 



*E.g., in Goccidoxenus codops, see fig- 2 a, b, p, 239. 

 (C326) C 



